net: ipv6: fix wrong ping_v6_sendmsg return value

ping_v6_sendmsg currently returns 0 on success. It should return
the number of bytes written instead.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c
index 10b9755..18f19df 100644
--- a/net/ipv6/ping.c
+++ b/net/ipv6/ping.c
@@ -191,7 +191,10 @@
 	}
 	release_sock(sk);
 
-	return err;
+	if (err)
+		return err;
+
+	return len;
 }
 
 #ifdef CONFIG_PROC_FS